A WebmasterWorld thread has numerous reports that the AdWords Editor is no longer downloading CPC (cost per click) placement targeted campaigns.
One user reported the following problem:
I created a CPC placement targeted campaign. I went to download it in adwords editor so I can bulk import some ads.But adwords editor ignores that campaign and says there is "nothing to download."
Others have validated that they are also experiencing the same issues.
AdWordsAdvisor has promised to look into the issue, but has not yet confirmed it is an issue on Google's side.
I'll look into this, and post again when I know more.
Forum discussion at WebmasterWorld.